org.openrewrite.java.migrate.lombok.LombokValToFinalVar Maven / Gradle / Ivy

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Migrate to later Java versions. Automatically.
There is a newer version: 3.0.1
/*
 * Copyright 2022 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 

 * https://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.openrewrite.java.migrate.lombok;

import org.openrewrite.ExecutionContext;
import org.openrewrite.Preconditions;
import org.openrewrite.Recipe;
import org.openrewrite.TreeVisitor;
import org.openrewrite.internal.ListUtils;
import org.openrewrite.java.JavaIsoVisitor;
import org.openrewrite.java.JavaTemplate;
import org.openrewrite.java.RemoveImport;
import org.openrewrite.java.search.MaybeUsesImport;
import org.openrewrite.java.search.UsesType;
import org.openrewrite.java.tree.J;
import org.openrewrite.java.tree.TypeUtils;

import java.time.Duration;
import java.util.Collections;
import java.util.Set;

public class LombokValToFinalVar extends Recipe {

    private static final String LOMBOK_VAL = "lombok.val";
    private static final String LOMBOK_VAR = "lombok.var";

    @Override
    public String getDisplayName() {
        return "Prefer `final var` over `lombok.val`";
    }

    @Override
    public String getDescription() {
        return "Prefer the Java standard library's `final var` and `var` over third-party usage of Lombok's `lombok.val` and `lombok.var` in Java 10 or higher.";
    }

    @Override
    public Set getTags() {
        return Collections.singleton("lombok");
    }

    @Override
    public Duration getEstimatedEffortPerOccurrence() {
        return Duration.ofMinutes(1);
    }

    @Override
    public TreeVisitor getVisitor() {
        TreeVisitor check = Preconditions.or(
                new UsesType<>(LOMBOK_VAL, false),
                // The parser does not recognize `var` as coming from Lombok, which happens to align with what we want
                new MaybeUsesImport<>(LOMBOK_VAR));
        return Preconditions.check(check, new LombokValToFinalVarVisitor());
    }

    private static class LombokValToFinalVarVisitor extends JavaIsoVisitor {
        @Override
        public J.CompilationUnit visitCompilationUnit(J.CompilationUnit compilationUnit, ExecutionContext ctx) {
            // Force remove `lombok.var` import; as the parser does not recognize `var` as coming from Lombok
            RemoveImport op = new RemoveImport<>(LOMBOK_VAR, true);
            if (!getAfterVisit().contains(op)) {
                doAfterVisit(op);
            }
            return super.visitCompilationUnit(compilationUnit, ctx);
        }

        @Override
        public J.VariableDeclarations visitVariableDeclarations(J.VariableDeclarations mv, ExecutionContext ctx) {
            J.VariableDeclarations varDecls = super.visitVariableDeclarations(mv, ctx);
            if (TypeUtils.isOfClassType(varDecls.getType(), LOMBOK_VAL) ||
                (varDecls.getTypeExpression() instanceof J.Identifier && ((J.Identifier) varDecls.getTypeExpression()).getSimpleName().equals("val"))) {
                maybeRemoveImport(LOMBOK_VAL);

                J.VariableDeclarations.NamedVariable nv = mv.getVariables().get(0);
                String finalVarVariableTemplateString;
                Object[] args;
                if (nv.getInitializer() == null) {
                    finalVarVariableTemplateString = "final var #{}";
                    args = new Object[]{nv.getSimpleName()};
                } else {
                    finalVarVariableTemplateString = "final var #{} = #{any()};";
                    args = new Object[]{nv.getSimpleName(), nv.getInitializer()};
                }
                varDecls = JavaTemplate.builder(finalVarVariableTemplateString)
                        .contextSensitive()
                        .build()
                        .apply(updateCursor(varDecls), varDecls.getCoordinates().replace(), args);

                if (nv.getInitializer() != null) {
                    varDecls = varDecls.withVariables(ListUtils.map(varDecls.getVariables(), namedVar -> namedVar
                            .withInitializer(namedVar.getInitializer().withPrefix(nv.getInitializer().getPrefix()))));
                }
            }
            return varDecls;
        }
    }
}